I. Data Set Descriptors A. Title: Christopher B. Craft. 2018. SALTEx soil oxidation-reduction (redox) potential measurements from the GCE LTER Seawater Addition Long-Term Experiment (SALTEx) between July 2016 and March 2017. Georgia Coastal Ecosystems LTER Data Catalog (data set POR-GCED-1802; http://gce-lter.marsci.uga.edu/public/app/dataset_details.asp?accession=POR-GCED-1802) B. Accession Number: POR-GCED-1802 C. Description 1. Originator(s): Name: Christopher B. Craft Address: Indiana University - School of Public and Environmental Affairs Room 408. MSB II. Bloomington, Indiana 47405 Country: USA Email: ccraft@indiana.edu 2. Abstract: SALTEx (Seawater Addition Long-Term Experiment) is a field experiment designed to simulate saltwater intrusion in a tidal freshwater wetland to predict how chronic (Press) and acute (Pulse) salinization will affect this and other tidal freshwater ecosystems. The SALTEx experiment was initiated in 2012 and consists of 31 field plots , each 2.5 m on a side. There are three treatments (Press, Pulse, and Fresh) and two types of controls (with and without sides), each consisting of six replicates. The Press treatment plots receive regular (4 times each week) additions of a mixture of seawater and fresh river water. Pulse plots receive the same mixture of seawater and river water during September and October, which is historically a time of low flow in the river when natural saltwater intrusion occurs. The Fresh treatment plots receive regular additions of fresh river water. Treatment water is added during low tide to facilitate its infiltration into the soil, and all plots are inundated by astronomical tides at high tide. Response measurements include porewater chemistry, specifically concentrations of chloride, sulfate, sulfide, dissolved organic carbon (DOC), ammonium-N, nitrate/nitrite-N, dissolved reactive phosphorus, total phosphorus, total nitrogen, organic nitrogen, carbon:nitrogen ratio, organic-carbon:organic-nitrogen ratio, and pH. 3. Study Type: Directed Study 4. Study Themes: Pore-water Chemistry, Chemistry 5. LTER Core Areas: Disturbance Patterns 6. Georeferences: none 7. Submission Date: Feb 20, 2018 D. Keywords: Disturbance Patterns, GCE, Georgia, Georgia Coastal Ecosystems, LTER, organic matter, Sapelo Island, USA II. Research Origin Descriptors A. Overall Project Description 1. Project Title: Georgia Coastal Ecosystems LTER Project III 2. Principal Investigators: Name: Merryl Alber Address: Dept. of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: malber@uga.edu 3. Funding Period: Nov 01, 2012 to Nov 01, 2018 4. Objectives: The research proposed for GCE-III is designed to address how variations in salinity and inundation, driven by climate change and anthropogenic factors, affect biotic and ecosystem responses at different spatial and temporal scales, and to predict the consequences of these changes for habitat provisioning and carbon (C) sequestration across the coastal landscape. 5. Abstract: The Georgia Coastal Ecosystems (GCE) LTER is located along three adjacent sounds on the Atlantic coast and includes both intertidal marshes and estuaries. Long-term drivers of climate change, sea level rise and human alterations of the landscape will cause transitions in dominant habitat types (state changes) within the GCE domain by changing the amounts and patterns of water delivery across the landscape. These changes in water delivery can be conceptualized as presses and pulses in river inflow, local runoff, groundwater input, and tidal inundation, which will in turn manifest themselves as changes in salinity and inundation patterns in the domain. The research proposed for GCE-III is designed to address how variations in salinity and inundation, driven by climate change and anthropogenic factors, affect biotic and ecosystem responses at different spatial and temporal scales, and to predict the consequences of these changes for habitat provisioning and carbon (C) sequestration across the coastal landscape. The goals are to: 1) Track long-term changes in climate and human actions in the watershed and adjacent uplands, and evaluate the effects of these drivers on domain boundary conditions. 2) Describe temporal and spatial variability in physical, chemical, geological and biological, and to evaluate how they are affected by variations in river inflow and other boundary conditions. 3) Characterize the responses of three dominant habitats in the domain to pulses and presses in salinity and inundation. 4) Describe patterns of habitat provisioning and C sequestration and export in the GCE domain, and to evaluate how these might be affected by changes in salinity and inundation. These efforts will be synthesized into a synoptic understanding of both biotic and ecosystem responses to variations in salinity and inundation driven by climate change and human activities, which will be used to assess thresholds between habitats and the potential for state changes in the domain. 6. Funding Source: NSF OCE 1237140 B. Sub-project Description 1. Site Description a. Geographic Location: SALTEx -- SALTEx Research Site, Champney Island, Georgia, USA Coordinates: SALTEx -- NW: 081 28 01.91 W, 31 20 23.40 N NE: 081 27 58.28 W, 31 20 23.40 N SE: 081 27 58.28 W, 31 20 20.23 N SW: 081 28 01.91 W, 31 20 20.23 N b. Physiographic Region: SALTEx -- unspecified c. Landform Components: SALTEx -- unspecified d. Hydrographic Characteristics: SALTEx -- unspecified e. Topographic Attributes: SALTEx -- unspecified f. Geology, Lithology and Soils: SALTEx -- unspecified g. Vegetation Communities: SALTEx -- Zizaniopsis, Spartina cynosuroides h. History of Land Use and Disturbance: none recorded i. Climate: Climate summary for Sapelo Island, Georgia, based on NWS data from 1980-2010: Daily-aggregated Values: Mean (sample standard deviation) mean air temperature: 20.09°C (7.28°C) minimum air temperature: 15.02°C (7.96°C) maximum air temperature: 24.82°C (6.98°C) total precipitation: 3.26mm (10.3mm) Yearly-aggregated Daily Values: Mean (sample standard deviation) total precipitation (1980-2010): 1124mm (266mm) 2. Experimental or Sampling Design a. Design Characteristics: SALTEx was initiated in 2012 (measurements began in 2014) and consists of 31 field plots, each 2.5 m on a side. There are three treatments (Press, Pulse, and Fresh) and two types of controls (with and without sides), each consisting of six replicates. The replicates are blocked by elevation in statistical analyses. The Press treatment plots receive regular (4 times each week) additions of a mixture of seawater and fresh river water. Pulse plots receive the same mixture of seawater and river water during September and October, which is historically a time of low flow in the river when saltwater intrusion naturally occurs. The Fresh treatment plots receive regular additions of fresh river water. Response measurements include porewater chemistry and soil oxidation-reduction (redox) potential. Compared to the controls, we expect redox potential to be lower in the plots that receive experimental water additions (fresh, pulse, and press) and lowest in the press plots. b. Permanent Plots: none c. Data Collection Duration and Frequency: We measured redox potential in each plot every 3 months starting in July 2016. We take 4 measurements in each plot to account for spatial variability. Beginning of Observations: Jul 11, 2016 End of Observations: Mar 09, 2017 3. Research Methods a. Field and Laboratory Methods: Method 1: Oxidation-Reduction -- Calibrate Redox probe according to the GCE protocol. Method 2: Redox Probe Field -- Soil oxidataion-reduction potenital was measured at a depth fo 10 cm using the Redox probe. b. Protocols: Method 1: Oxidation-Reduction Potential Probe Protocol Organization: Georgia Coastal Ecosystems LTER Description: Oxidation-Reduction Potential Probe Protocol. Source: American Public Health Association (APHA) 1998. Oxidation-Reduction Potential (ORP). p. 2-75-2-78. In Standard methods for the examination of water and wastewater, 20th ed. American Public Health Association, Washington, DC, USA. URL: https://gce-lter.marsci.uga.edu/private/app/resource_details.asp?id=841 Method 2: Redox Probe Field Methods Organization: Georgia Coastal Ecosystems LTER Description: Protocol for using the Redox probe in the field URL: https://gce-lter.marsci.uga.edu/private/app/resource_details.asp?id=842 c. Instrumentation: Method 1: Orion Model 250A Portable pH/ISES meter, accumet double junction reference electrode Method 2: Orion Model 250A Portable pH/ISES meter, accumet double junction reference electrode d. Taxonomy and Systematics: Method 1: not applicable Method 2: not applicable e. Speclies List: f. Permit History: Method 1: not applicable Method 2: Army Corps of Engineers Permit SAS-2011-00748, Georgia DNR Coastal Resources Division Letter of Permission issued on Aug. 9 2011 (File 072911.0000_) 4. Project Personnel a. Personnel: 1: Christopher B. Craft 2: Sarah Widney 3: Dontrece Smith 4: Elena Solohin b. Affiliations: 1: Indiana University at Bloomington, Bloomington, Indiana 2: Indiana University, Bloomington, Indiana 3: University of Georgia Marine Institute, Sapelo Island, Georgia 4: Indiana University, Bloomington, Indiana III. Data Set Status and Accessibility A. Status 1. Latest Update: 23-Feb-2018 2. Latest Archive Date: 23-Feb-2018 3. Latest Metadata Update: 23-Feb-2018 4. Data Verification Status: New Submission B. Accessibility 1. Storage Location and Medium: Stored at GCE-LTER Data Management Office Dept. of Marine Sciences Univ. of Georgia Athens, GA 30602-3636 USA on media: electronic data download (WWW) or compact disk 2. Contact Person: Name: Wade M. Sheldon, Jr. Address: Dept. of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: sheldon@uga.edu 3. Copyright Restrictions: not copyrighted 4. Restrictions: This information is licensed under a Creative Commons Attribution 4.0 International License (see: https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) has an ethical obligation to cite it appropriately in any publication that results from its use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the authors. The Data User should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. a. Release Date: Affiliates: Feb 20, 2018, Public: Feb 20, 2019 b. Citation: Data provided by the Georgia Coastal Ecosystems Long Term Ecological Research Project, supported by funds from NSF OCE 1237140 (data set POR-GCED-1802) c. Disclaimer: The user assumes all responsibility for errors in judgement based on interpretation of data and analyses presented in this data set. 5. Costs: free electronic data download via WWW, distribution on CD may be subject to nominal processing and handling fee IV. Data Structural Descriptors A. Data Set File 1. File Name: POR-GCED-1802_1_0.CSV 2. Size: 495 records 3. File Format: ASCII text (comma-separated value format) 3a. Delimiters: single comma 4. Header Information: 5 lines of ASCII text 5. Alphanumeric Attributes: 6. Quality Control Flag Codes: Q = questionable value, I = invalid value, E = estimated value 7. Authentication Procedures: 8. Calculations: 9. Processing History: Software version: GCE Data Toolbox Version 3.9.7b (17-Jul-2017) Data structure version: GCE Data Structure 1.1 (29-Mar-2001) Original data file processed: POR-GCED-1802.txt (495 records) Data processing history: 23-Feb-2018: new GCE Data Structure 1.1 created ('newstruct') 23-Feb-2018: 495 rows imported from ASCII data file 'POR-GCED-1802.txt' ('imp_ascii') 23-Feb-2018: 83 metadata fields in file header parsed ('parse_header') 23-Feb-2018: data structure validated ('gce_valid') 23-Feb-2018: Q/C flagging criteria applied, 'flags' field updated ('dataflag') 23-Feb-2018: updated 1 metadata fields in the Dataset sections ('addmeta') 23-Feb-2018: updated 1 metadata fields in the Dataset sections ('addmeta') 23-Feb-2018: updated 1 metadata fields in the Dataset sections ('addmeta') 23-Feb-2018: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 23-Feb-2018: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement sections ('addmeta') 23-Feb-2018: updated 1 metadata fields in the Dataset sections ('addmeta') 23-Feb-2018: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 23-Feb-2018: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement sections ('addmeta') 23-Feb-2018: Q/C Criteria of column Elevation changed from 'x<1.3418='I';x>1.495='I';x<1.3418='Q';x>1.495='Q'' to 'x<1.3417='I';x>1.495='I';x<1.3417='Q';x>1.495='Q' ('ui_editor') 23-Feb-2018: Q/C flagging criteria applied for column(s) Elevation, 'flags' field updated ('dataflag') 23-Feb-2018: updated 6 metadata fields in the Data sections ('addmeta') 23-Feb-2018: updated 15 metadata fields in the Status, Data sections to reflect attribute metadata ('updatecols') 23-Feb-2018: parsed and formatted metadata ('listmeta') B. Variable Information 1. Variable Name: column 1. Sample_Date column 2. Treatment column 3. Replicate column 4. Elevation column 5. Probe_Number column 6. Corrected_Potential 2. Variable Definition: column 1. Date the measurement was made column 2. Sample treatment column 3. Replicate column 4. Mean plot elevation relative to MLW column 5. Platinum electrode used for measurement column 6. Soil oxidation-reduction potential at 10 cm depth 3. Units of Measurement: column 1. MM/DD/YYYY column 2. none column 3. none column 4. m column 5. none column 6. mV 4. Data Type a. Storage Type: column 1. string column 2. string column 3. integer column 4. floating-point column 5. integer column 6. floating-point b. Variable Codes: Treatment: C=Control, CS=Control w/ sides, F=Fresh, PR=Press, PU=Pulse, AltRiver=Altamaha River, Tank=Mixing tank, MerDock=Meridian Dock c. Numeric Range: column 1. (none) column 2. (none) column 3. 1 to 9 column 4. 1.3418 to 1.495 column 5. 1 to 11 column 6. -262.2 to 696.5 d. Missing Value Code: 5. Data Format a. Column Type: column 1. text column 2. text column 3. numerical column 4. numerical column 5. numerical column 6. numerical b. Number of Columns: 6 c. Decimal Places: column 1. 0 column 2. 0 column 3. 0 column 4. 5 column 5. 0 column 6. 1 6. Logical Variable Type: column 1. datetime (none) column 2. nominal (none) column 3. ordinal (discrete) column 4. data (continuous) column 5. ordinal (discrete) column 6. data (continuous) 7. Flagging Criteria: column 1. none column 2. none column 3. x<1="I";x>9="I";x<1="Q";x>9="Q" column 4. x<1.3417="I";x>1.495="I";x<1.3417="Q";x>1.495="Q" column 5. x<1="I";x>11="I";x<1="Q";x>11="Q" column 6. x<-500="I";x>700="I";x<-300="Q";x>700="Q" C. Data Anomalies: n/a V. Supplemental Descriptors A. Data Acquisition 1. Data Forms: Excel spreadsheets 2. Form Location: secure server at Indiana University 3. Data Entry Validation: n/a B. Quality Assurance/Quality Control Procedures: C. Supplemental Materials: n/a D. Computer Programs: Microsoft Excel 2007 E. Archival Practices: F. Publications: not specified G. History of Data Set Usage 1. Data Request History: not specified 2. Data Set Update History: none 3. Review History: none 4. Questions and Comments from Users: none